【英文版】USP32富马酸亚铁含量的测定

美国药典32版（USP32）英文版富马酸亚铁含量的测定C4H2FeO4 169.902-Butenedioic acid, (E)-, iron(2+) salt. 【2-反丁烯二酸，（E）-亚铁盐】Iron(2+) fumarate 【富马酸亚铁】»Ferrous Fumarate contains not less than 97.0 percent and not more than 101.0 percent of C4H2FeO4, calculated on the dried basis.Packaging and storage— Preserve in well-closed containers.Identification【鉴别】—A: To 1.5 g add 25 mL of dilute hydrochloric acid (1 in 2). Dilute with water to 50 mL, heat to dissolve, then cool, filter on a fine-porosity【细孔径】, sintered-glasscrucible【烧结玻璃坩埚】, wash the precipitate【沉淀】with dilute hydrochloric acid (3 in 100), saving the filtrate for Identification test B, and dry the precipitate at 105℃: the IR absorption【外红吸收】of a potassium bromide【溴化钾】dispersion of the dried precipitate so obtained exhibits maxima【最大值】only at the same wavelengths as that of a similar preparation of USP Fumaric Acid RS.B: A portion of the filtrate obtained in the preceding test responds to the tests for Iron<191>.Loss on drying <731>— Dry it at 105℃for 16 hours: it loses not more than 1.5% of its weight.Sulfate【硫酸盐】—Transfer【移取】1.0 g to a 250-mL beaker【烧杯】, add 100 mL of water, and heat on a steam bath【蒸气浴】, adding hydrochloric acid dropwise【逐滴加入盐酸】, until complete solution【溶液】is effected (about 2 mL of the acid will be required).Filter【过滤】the solution if necessary, and dilute【稀释】the filtrate【滤液】with water to 100 mL. Heat the filtrate to boiling【沸腾】,add 10 mL of barium chlorideTS【氯化钡试液，TS=Test Solution 试液】, warm on a steam bath for 2 hours, cover, and allow to stand for【静置】16 hours. (If crystals【结晶】of ferrous fumarate form【形成】, warm the solution on the steam bath to dissolve【溶解】them.)Pass the solution through ashless filter paper【无灰滤纸】, wash theresidue【滤渣】with hot water until, with the addition of ammonium sulfideTS【硫化铵试液，TS=Test Solution 试液】, a black precipitate【沉淀】is no longer formed in the filtrate, and transfer the paper containing the residue to a taredcrucible【已称重的坩埚】.Char【碳化】the paper, without burning, and ignite the crucible【灼烧坩埚】and its contents at 600℃ to constant weight【恒重】: each mg of residue【残留物】is equivalent to【相当于】0.412 mg of SO4. Not more than 0.2% is found.Arsenic, Method I <211>— Transfer 2.0 g to a beaker, and add 10 mL of water and 10 mL of sulfuric acid. Warm to precipitate the fumaric acid completely, cool, add 30 mL of water, and filter into a 100-mL volumetric flask【容量瓶】. Wash the precipitate with water, adding the washings to the flask, add water to volume, and mix. Transfer 50.0 mL of this solution into the arsine generator flask【砷化氢发生器】, and dilute with water to 55 mL: the resulting solution meets the requirements of the test, the addition of 20 mL of 7 N sulfuric acid specified【指定】 for Procedure being omitted【省略】. The limit is 3 ppm.Limit of ferric iron— Transfer 2.0 g, accurately weighed【精确称量】, to a glass-stoppered【玻璃塞】, 250-mL conical flask【锥形瓶】, add 25 mL of water and 4 mL of hydrochloric acid, and heat on a hot plate【电炉】until solution is complete. Insert the stopper in the flask, and cool to room temperature. Add 3 g of potassium iodide【碘化钾】, insert the stopper in the flask, swirl to mix【摇匀】, and allow to stand in the dark for 5 minutes. Remove the stopper, add 75 mL of water, and titrate with 0.1 N sodium thiosulfate VS【硫代硫酸钠滴定液】, adding 3 mL of starch TS【淀粉溶液】as the end-point is approached【临近终点】. Not more than 7.16 mL of 0.1 N sodium thiosulfate is consumed (2.0%).Limit of lead— [note—For the preparation of all aqueous solutions【水溶液】and for the rinsing【冲洗】of glassware before use, employ water【用水】that has been passed through a strong-acid【强酸】, strong-base【强碱】, mixed-bed ion-exchangeresin【混合床离子交换树脂】before use. Select all reagents【试剂】to have as low a content of lead as practicable, and store all reagent solutions in containers of borosilicate glass【硼硅酸盐玻璃】. Clean glassware before use by soaking【浸泡】in warm 8 N nitric acid for 30 minutes and by rinsing with deionized water【去离子水】.]Ascorbic acid【抗坏血酸】–sodium iodide solution【碘化钠溶液】— Dissolve 20 g of ascorbic acid and 38.5 g of sodium iodide in water in a 200-mL volumetric flask, dilute with water to volume, and mix.Trioctylphosphine oxide solution【三正辛基氧膦溶液】— [Caution—This solution causes irritation【刺激】. Avoid contact with eyes, skin, and clothing. Take special precautions in disposing of unused portions of solutions to which this reagent is added. ] Dissolve 5.0 g of trioctylphosphine oxide in 4-methyl-2-pentanone【4-甲基-2-戊酮】in a 100-mL volumetric flask, dilute with the same solvent to volume, and mix.Standard solution and Blank— Transfer 5.0 mL of Lead Nitrate StockSolution【硝酸铅储备液】, prepared as directed in the test for Heavy Metals <231>, to a 100-mL volumetric flask, dilute with water to volume, and mix. Transfer 2.0 mL of the resulting solution to a 50-mL beaker. To this beaker and to a second, empty beaker (Blank) add 6 mL of nitric acid and 10 mL of perchloric acid【高氯酸】, and evaporate【蒸发】 in a hood【橱】to dryness. [Caution—Use perchloric acid in a well-ventilated【通风良好】fume hood【通风橱】 with proper precautions【适当的预防措施】. ] Cool, dissolve the residues in 10 mL of 9 N hydrochloric acid, and transfer with the aid of about 10 mL of water to separate 50-mL volumetric flasks. To each flask add 20 mL of Ascorbic acid–sodium iodide solution and 5.0 mL of Trioctylphosphine oxide solution, shake for 30 seconds, and allow to separate. Add water to bring the organic solvent layer into the neck of each flask, shake again, and allow to separate. The organic solvent layers are the Blank and the Standard solution, and they contain 0.0 and 2.0 µg of lead per mL, respectively.Test solution— Add 1.0 g of Ferrous Fumarate to a 50-mL beaker, and add 6 mL of nitric acid and 10 mL of perchloric acid. [Caution—Use perchloric acid in a well-ventilated fume hood with proper precautions. ] Cover with a ribbed【棱纹】watch glass【表面皿】, and heat in a hood until completely dry. Cool, dissolve the residue in 10 mL of 9 N hydrochloric acid, and transfer with the aid of about 10 mL of water to a 50-mL volumetric flask. Add 20 mL of Ascorbic acid–sodium iodide solution and 5.0 mL of Trioctylphosphine oxide solution, shake for 30 seconds, and allow to separate. Add water to bring the organic solvent layer into the neck of the flask, shake again, and allow to separate. The organic solvent layer is the Test solution.Procedure【步骤】— Concomitantly【伴随，同时】determine the absorbances of the Blank, Standard solution, and Test solution at the lead emission line【铅发射线】at 283.3 nm with a suitable atomic absorption spectrophotometer (see Spectrophotometry and Light-scattering <851>) equipped with a lead hollow-cathode lamp【铅空心阴极灯】and an air–acetylene flame【空气-乙炔火焰】, using the blank to set the instrument to zero. In asuitable analysis, the absorbance of the Standard solution and the absorbance of the Blank are significantly different: the absorbance of the Test solution does not exceed that of the Standard solution (0.001%).Mercury【汞】— [notes—(1) Carry out【完成】this procedure in subdued light【避光】, since mercuric dithizonate【双硫腙汞】is light-sensitive【对光敏感】. (2) For preparation of solutions, see Mercury <261>.] Dissolve about 1 g, accurately weighed, in 30 mL of dilute nitric acid (1 in 10), with the aid of heat, on a steam bath. Cool quickly by immersion in an ice bath, and pass through a fine-porosity filter that previously has been washed with dilute nitric acid (1 in 10) and water. To the filtrate add 20 mL of sodium citratesolution【柠檬酸钠溶液】(1 in 4) and 1 mL of Hydroxylamine HydrochlorideSolution【盐酸羟胺溶液】.Prepare a control solution【对照溶液】consisting of 3.0 mL of Standard Mercury Solution, 30 mL of dilute nitric acid (1 in 10), 5 mL of sodium citrate solution (1 in 4), and 1 mL of Hydroxylamine Hydrochloride Solution.Using ammonium hydroxide【氨水】, adjust the control solution to a pH of 1.8, determined potentiometrically【电位滴定，pH计】, and transfer to a separator【分离器】. Using sulfuric acid, adjust the test solution to a pH of 1.8, determined potentiometrically, and transfer to a separator. Treat the solution under test and the control solution in parallel 【平行】as follows. Extract with two 5-mL portions of Dithizone ExtractionSolution【双硫腙提取液】and 5 mL of chloroform【三氯甲烷】, pooling【收集】the chloroform extracts in a second separator. Add 10 mL of dilute hydrochloric acid (1 in 2), shake, allow the layers to separate, and discard the chloroform layer. Wash the acid extract with 3 mL of chloroform, and discard the washing. Add 0.1 mL of edetate disodiumsolution【乙二胺四乙酸二钠溶液】(1 in 50) and 2 mL of 6 N acetic acid【乙酸】, mix, and add slowly 5 mL of ammonium hydroxide. Close the separator, cool it under cold running water, and dry its outer surface. Remove the stopper, and pour the contents into a beaker. Adjust the solution under test and the control solution to a pH of 1.8 in the same manner asbefore, and return the solutions to their respective separators. Add 5.0 mL of Diluted Dithizone Extraction Solution, shake vigorously, and allow the layers to separate. Using Diluted Dithizone Extraction Solution as a color blank, compare the colors developed in the chloroform layers of the solution under test and the control solution: the color developed by the solution under test is not more intense than that developed by the control solution (3 µg per g).Assay【试验】—Transfer【移取】500 mg of Ferrous Fumarate【富马酸亚铁】, accuratelyweighed【准确称重】, to a 500-mL conical flask【锥形瓶】, and add 25 mL of dilute hydrochloric acid (2 in 5)【(2→5)的稀盐酸】.Heat to boiling【加热至沸】, and add a solution of 5.6 g of stannouschloride【氯化亚锡】in 50 mL of dilute hydrochloric acid (3 in 10)【(3→10)稀盐酸】dropwise【逐滴】until the yellow color disappears【黄色消失】, then add 2 drops in excess【过量2滴】.Cool the solution【溶液冷却】in an ice bath【冰浴】to room temperature【室温】, add 10 mL of mercuric chloride solution (1 in 20)【(1→20)氯化汞溶液】, and allow to stand for 5 minutes【静置5分钟】.Add 200 mL of water, 25 mL of dilute sulfuric acid (1 in 2)【(1→2)稀盐酸】, and 4 mL of phosphoric acid【磷酸】, then add 2 drops of orthophenanthrolineTS【邻菲罗啉(邻二氮菲)试液，TS=Test Solution 试液】, and titrate with 0.1 N ceric sulfate VS【用0.1N(0.1mol/L)硫酸铈标准滴定液滴定，VS=Volumetric Solution滴定液】.Perform a blank determination【空白测定】, and make any necessarycorrection【做必要的修正】. Each mL of 0.1 N ceric sulfate is equivalent to【等于】16.99 mg of C4H2FeO4.Comments by Peng·L2014年9月19日微商货源网 GcIG7wxDH4st。